[OSM-talk-fr] Limites administratives espagnoles et frontières avec la France

[Frédéric Rodrigo]

Le samedi 05 décembre 2009 23:00:36, Skywave a écrit :
> 2009/12/5 Christophe Merlet (RedFox) <redfox at redfoxcenter.org>:
> > Le samedi 05 décembre 2009 à 14:56 +0100, Skywave a écrit :
> >> I was talking about the comparison between Cadastre and the Spanish
> >> Data, i don't have the exact data of the borderstones, but the Spanish
> >> data seems to be following it more, the Cadastre data has more curves
> >> but the difference is measured in centimers not meters. There are a
> >> few bordersstones in the database, one by me, a couple by others, they
> >> match both the Cadastre and the Spanish data. But imo if you would
> >> draw a line between each borderstone it would look more like the data
> >> from the Spanish source
> >
> > Now, I know the tag for borderstone (historic=boundary_stone) :)
> > but it's not rendered by mapnik :(
> >
> >> And i know the difference between cadastre, CIA, and the Spanish data,
> >> as they were imported by me in that region. Cadastre.fr has of course
> >> also country borders as they share borders, the Spanish data i got
> >> from a file sent by the importer, the CIA data should be deleted as
> >> soon as possible.
> >
> > OK, that allright.
> >
> >> The data from the French cadastre is just fine for the purpose in OSM,
> >> i have only slightly altered the existing Cadastral borders in the
> >> Pyrenees Orientales: i cleaned out some unnecessary nodes and cutted
> >> it in pieces to fit in the Spanish relations. I've deleted the
> >> Andorrian-Spanish border, as it was from the CIA world databank
> >>
> >> http://www.openstreetmap.pl/balrog/limites-omitidos.osm.bz2
> >
> > Beware with your limits, it's not always better. It does not follow
> > natural border like river
> >
> > Arneguy
> > http://sautter.com/map/?zoom=16&lat=43.10889&lon=-1.28235&layers=00B000TF
> >FFFF
> >
> > Border stone #225
> > http://sautter.com/map/?zoom=18&lat=43.00806&lon=-1.14266&layers=00B000TF
> >FFFF (here, french cadastre is also not really exact :/ Track way from my
> > own GPS should be in France...)
> >
> >
> >        Librement,
> > --
> > Christophe Merlet (RedFox)
> 
> My piece of border mainly existed out of Col's and peaks, not many
> rivers, couple of streams probably.
> The limits will probably always be different in different sources and
> i presume nobody in the real world cares either about that small
> surface of rock ;). Openstreetmap will never be able to really check
> the whole border.
> For that borderstone, keep in mind, GPS isn't very precise either.

Visiblement il n'y a que 3 bornes déjà en place
http://cassini.toolserver.org/~kolossos/qtm2/featurelist.php?key=historic&value=boundary_stone&types=points-
areas-infos&BBOX=-2,43.5,3.5,42

De plus j'en ai trouvé approximativement 30 dans les repères géodésiques et de 
nivellements.

Il faudrais voir à faire une petit script pour importer des données depuis les 
CSV des fiches IGN, si ça n'a pas déjà été fait pour les châteaux d'eau.